Improvement in solar-time globes



T. R. TIMBY.

Solar Time Globe.

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UNITED STATES PATENT OFFICE.

THEODORE It. TIMBY, ()F SARATOGA SPRINGS, NEW YORK.

IMPROVEMENT lN SOLAPrTIME GLOBES.

Specification forming part of Letters Patent No. 39,183, dated July 7, 1863; Reissue No. 1,525, dated August 18,1863.

' verse vertical section of the same in a smaller scale than the previous figure.

Similar letters of reference indicate corresponding parts in the two figures.

The object of this invention is to arrange a terrestrial globe in such relation to a dialplate and index that the culminating time of the sun, and consequently the true solar time and also the clock or mean time and the difference of time on different localities of the globe, can beobserved simultaneously at any moment.

To enable-others skilled-in the art to make anduse my invention, I will proceed to describe it.

A represents a terrestrial globe, the axle a of which is brought in a horizontal position having its bearings in segmental arms I), which are secured to the case B, in which the globe revolves.

G is an annular dial-plate, which is divided off into twenty-four hours of the day, and each part is subdivided into thirty or sixty parts, to indicate the minutes. The dial-plate is secured to a ring, D, by means of setscrews 0, which pass through slots in the ring in such a manner that the dial can be adjusted in either direction. The ring D is secured to the globe by means of clamps d, which are so arranged that the globe can be readily shifted within the ring and brought in the desired relation toward the dial. The edge of the ring is provided with cogs e, which gear into a cog-wheel, E, to which a rotary motion is imparted by a clock-movement, or in any other desirable manner. The motion of this cog-wheel is so regulated that the ring D, and

with it the globe A four hours.

F is an index or pointer, which is firmly secured to the case B, and which points to the marks on the dial and to the various meridians marked on the globe as the same revolves under it.

The operation is as follows: As the globe revolves, the several meridians marked on the same pass through under the index F, and the time when the sun culminates on any part of the globe can thus be observed at a glance. At the same time the dial is adjusted to correspond to the clock-time of a certain location on the globefor instance, to that of Washington-my bringing the meridian of Washington in line with one of the figures 12 on the dial. In this position the ring D is secured to the globe and the globe is adjusted so that when the sun culminates the index stands exactly opposite to the figure 12 and to the meridian under said figure. If left thus, both the dial and the globe will indicate the solar time; but in order to obtain the clock or mean time the dial 0 is adjusted backward or forward by means of the set-screws 0, according to the equation of time on any day of the year, and when this is accomplished the solar time and mean time can be read ofl simultaneously. Furthermore, the observer is enabled to tell instantaneously the difference of time between certain localities-for instance, when the globe and dial are adjusted for Washington and the index points at five, it shows that it is five oclock in Washington. At the same moment the sun culminates in all localities situated under the upper half of the meridian which is opposite to the index at that moment, and it is midnight on all localities underthe lower half of said meridian, showing that there is a difference of time of five or seven hours between all localitiesunder said meridian and the localities under the meridian of Washington.

This time-globe is very simple in its construction, nothing being required but an or-' dinary clock-movement, the wheel E, toothed ring D, with the dial 0, and the globe and index to make up the whole mechanism, and it revolves once in twentywill not only be an oI-mu'nent to any room, but it will also be convenient to illustrate the dilierenee of time on diflerent localities oi the globe, and the difference between solar and mean time.

What claim ZLS new, and desire to secure by Letters Patent, is

1. A globe, A, surrounded by 21, ring or dial, 1), and revolved with the same once in twentyfour hours, in combination with a stationary index, l substantially in the nmnne and for the purpose specified.

2. lhe adjustable dial. (J, attached to the ring D, and revolving with the same and with the globe A. under it stationery i nde:.\', F, substentiall y as and for the purpose set forth.

'llfIlilODOlftE R. Tl M HY.

Witnesses:

Tnos. J. DOUGLAS, GEO. W. REED. 

